阅读说明：本技术 一种锂离子负极材料的制备方法及锂离子负极材料 (Preparation method of lithium ion negative electrode material and lithium ion negative electrode material ) 是由 梁光 马磊 段拴水 许晓落 于 2019-10-24 设计创作，主要内容包括：本发明具体涉及一种锂离子负极材料的制备方法,该制备方法包括将筛分工艺中产生的筛分废料进行再处理并用作锂离子负极材料的原料。本发明将现有技术中直接当作废品丢弃的筛分废料进行再处理,用于制备合格的负极材料,利用所述筛上废料制备出的负极材料,至少可以满足低端锂离子电池的负极材料的要求,并且显著降低了制造成本,充分利用了生产工艺中的废料,提高了物料的利用率,性价比高,是一种绿色环保的制备方法。本发明还涉及一种锂离子负极材料。(The invention particularly relates to a preparation method of a lithium ion negative electrode material. The invention reprocesses the screening waste which is directly discarded as waste in the prior art and is used for preparing qualified cathode materials, the cathode materials prepared by utilizing the screening waste can at least meet the requirements of cathode materials of low-end lithium ion batteries, the manufacturing cost is obviously reduced, the waste in the production process is fully utilized, the utilization rate of the materials is improved, the cost performance is high, and the preparation method is environment-friendly. The invention also relates to a lithium ion negative electrode material.)

1. A preparation method of a lithium ion negative electrode material is characterized by comprising the step of reprocessing screening waste materials generated in a screening process and using the screening waste materials as raw materials of the lithium ion negative electrode material.

2. The method for preparing the lithium ion negative electrode material according to claim 1, wherein the reprocessing of the screened waste comprises sequentially classifying, grinding, shaping, spheroidizing, carbonizing, and screening the mixed material;

preferably, the screening waste is firstly screened by a 200-mesh sieve, and undersize materials are sequentially subjected to grading, grinding, shaping and spheroidizing, carbonization and mixed material screening.

3. The preparation method of the lithium ion anode material according to claim 2, wherein the classification is to treat the screened waste by using a classifier 10-15KW, wherein the classification wheel is a vertical classification wheel, the induced draft fan is 40-60KW, the whole equipment is made of stainless steel, the equipment parameter classifier is 45-50HZ, and the induced draft fan is 40-80 degrees.

4. The preparation method of the lithium ion negative electrode material according to claim 2 or 3, wherein the milling is to perform granularity treatment on the classified screened waste material by using a mechanical mill, wherein the mechanical mill has a power of 40-60KW, 8-10 mill knives are arranged in the mill, the mill is matched with cyclone blanking, and the power of an induced draft fan is 40-60 KW.

5. The method for preparing the lithium ion anode material according to claim 4, wherein a fusion machine is used for shaping and spheroidizing, the diameter of the fusion machine is 500mm, and the rotating speed is 400-800 RPM/min.

6. The method for preparing a lithium ion negative electrode material according to claim 5, wherein the screened waste mixed pitch obtained after classification, grinding, shaping and spheroidizing is carbonized;

preferably, the volume distribution D50 of the asphalt is 5-15 μm, and the ratio of the asphalt to the screening waste is 1: 5 to 15.

7. The method for preparing a lithium ion anode material according to claim 6, wherein the carbonization is performed in a roller kiln, and a temperature profile in the roller kiln comprises 13 temperature intervals: at normal temperature of-200, 400, 500, 700, 800, 1200, 800 and temperature of 18-24, uniform temperature rise is carried out.

8. The preparation method of the lithium ion negative electrode material as claimed in claim 1, wherein the ash content of the screening waste generated in the screening process is not less than 4%, and the tap density is not more than 0.97g/cm³The specific surface area is more than or equal to 6.70m²The first efficiency is less than or equal to 89 percent.

9. A lithium ion negative electrode material, characterized by being obtained by the method for producing a lithium ion negative electrode material according to any one of claims 1 to 8.

10. The lithium ion negative electrode material of claim 9, wherein the ash content is not more than 0.01%, and the tap density is not less than 1.05/cm³Specific surface area is less than or equal to 1.50m²The capacity is more than or equal to 341mAh/g, and the first efficiency is more than or equal to 91.5 percent.

Technical Field

The invention belongs to the technical field of battery materials, and particularly relates to a preparation method of a lithium ion negative electrode material and the lithium ion negative electrode material.

Background

The negative electrode of the lithium ion battery is formed by uniformly coating a paste adhesive prepared by mixing a negative electrode active material carbon material or non-carbon material, a binder and an additive on two sides of a copper foil, drying and rolling. The negative electrode material is a main body for storing lithium in the lithium ion battery, so that lithium ions are inserted and removed in the charging and discharging processes, when the lithium battery is charged, lithium atoms in the positive electrode are ionized into lithium ions and electrons, and the lithium ions move to the negative electrode and synthesize the lithium atoms with the electrons. During discharge, lithium atoms are ionized from the surface of the negative electrode in the graphite crystal into lithium ions and electrons, and the lithium atoms are synthesized at the positive electrode. The negative electrode material mainly affects the energy density, the first efficiency, the cycle performance and the like of the lithium battery, and the performance of the negative electrode material also directly affects the performance of the lithium battery.

In the screening process of the existing preparation method of the cathode material, about 10% of waste materials (large particles, foreign matters and the like) are produced, and the materials are generally treated as waste materials (hereinafter referred to as oversize waste materials) and cannot be reasonably utilized, so that the materials are greatly wasted.

The present invention has been made in view of the above circumstances.

Disclosure of Invention

In order to solve the problems that the prior art cannot reasonably utilize the waste materials on the screen and cannot create more values, the invention provides a preparation method of a lithium ion negative electrode material with high cost performance.

The invention aims to provide a preparation method of a lithium ion negative electrode material, which comprises the step of reprocessing screening waste generated in a screening process and using the screening waste as a raw material of the lithium ion negative electrode material.

Further, the screening waste material reprocess including classifying, crocus, plastic balling, carbonization and compounding screening the screening waste material in proper order.

After the reprocessing technology is adopted, the ash content of the screening waste which can only be discarded originally is reduced, the granularity is reduced, the specific surface area is reduced, and the reprocessing technology can be basically used for preparing the negative electrode material of the low-end lithium ion battery, so that the effective utilization rate of the material is improved, the waste of raw materials is avoided, and the output and the economic benefit are improved.

Further, the screened waste is sieved by a 200-mesh sieve, and undersize materials are sequentially graded, ground, shaped, spheroidized, carbonized and mixed for screening.

Furthermore, in the preparation method of the lithium ion negative electrode material, the ash content of the screening waste material generated in the screening process is more than or equal to 4%.

Furthermore, the granularity D10 of undersize products obtained by sieving the waste materials generated in the sieving process through a 200-mesh sieve is 10-15 microns, the granularity D50 is 19-22 microns, and the granularity D90 is 45-55 microns.

Further, the tap density of undersize products obtained by sieving the sieving waste materials generated in the sieving process by a 200-mesh sieve is less than or equal to 0.97g/cm³The specific surface area is more than or equal to 6.70m²The first efficiency is less than or equal to 89 percent.

Further, in the preparation method of the lithium ion cathode material, the classification is to treat the screened waste by adopting a classifier 10-15KW, wherein the classification wheel adopts a vertical type classification wheel with vertical shape, the induced draft fan is 40-60KW, the whole equipment is made of stainless steel, the equipment parameter is 45-50HZ, and the induced draft fan is 40-80 degrees.

The ash is the impurity such as dust, fibre that introduces in the production process, goes out the impurity screening of whole batch in the screening process, gets into in the screening waste material, so the ash content of screening waste material is higher. Because the density of the ash is much lower than that of the effective components which can be used for the cathode material, the ash can be simply and efficiently removed by adopting the classification method, the content of the ash can be controlled to be lower than 0.01 percent, and the performance of the cathode material is further improved when the cathode material is used.

Further, in the preparation method of the lithium ion cathode material, the milling is to perform granularity treatment on the screened waste obtained after classification by adopting a mechanical mill, wherein the power of the mechanical mill is 40-60KW, 8-10 mill knives are arranged in the mill, the material is fed by matching cyclone, the power of an induced draft fan is 40-60KW, and the material is made of stainless steel.

Further, in the preparation method of the lithium ion negative electrode material, a fusion machine is adopted for shaping and spheroidizing, wherein the diameter of the fusion machine is 500mm, and the rotating speed is 400-800 RPM/min.

The grinding and shaping ballThe particle morphology of the screened waste can be improved by the chemical process, so that the tap density of the negative electrode material can be improved conveniently, and the tap density can be not more than 0.97g/cm before treatment³Is increased to be more than or equal to 1.05g/cm³。

Further, in the preparation method of the lithium ion negative electrode material, the screened waste mixed asphalt obtained after grading, grinding, shaping and spheroidizing is carbonized.

Preferably, the volume distribution D50 of the asphalt is 5-15 μm, and the ratio of the asphalt to the screening waste is 1: 5 to 15.

Further, in the preparation method of the lithium ion negative electrode material, the carbonization is performed in a roller kiln, and a temperature curve in the roller kiln comprises 13 temperature intervals: at normal temperature of-200, 400, 500, 700, 800, 1200, 800 and temperature of 18-24, uniform temperature rise is carried out.

After the carbonization process is adopted, the specific surface area of the screened waste is obviously reduced, and the first efficiency is obviously improved.

Further, the screened waste materials are sequentially graded, ground, shaped, spheroidized and carbonized, and then 10m of the waste materials are utilized³And mixing and screening the materials by a mixer and an ultrasonic vibration screen to prepare the cathode material. Another object of the present invention is to provide a lithium ion negative electrode material with high cost performance, which is obtained by using the preparation method of the lithium ion negative electrode material according to any one of the above.

Further, the lithium ion negative electrode material with high cost performance meets the following conditions: ash content is less than or equal to 0.01 percent, tap density is more than or equal to 1.05g/cm³Specific surface area is less than or equal to 1.50m²The capacity is more than or equal to 341mAh/g, and the first efficiency is more than or equal to 91.5 percent.

Compared with the prior art, the invention has the following beneficial effects:

the invention reprocesses the screening waste which is directly discarded as waste in the prior art and is used for preparing qualified cathode materials, the cathode materials prepared by utilizing the screening waste can at least meet the requirements of cathode materials of low-end lithium ion batteries, the manufacturing cost is obviously reduced, the waste in the production process is fully utilized, the utilization rate of the materials is improved, the cost performance is high, and the preparation method is environment-friendly.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.